pigeons pecking

[Owl pigeons]

I have a pair of German Owl pigeons that are pecking the feathers off each other's chests and now there are bare spots of pink skin the size of a dime. they are fed plenty of commercial pigeon feed, water, and grit. They are kept in an outdoor cage.
Is this normal pigeon behavior?

 

[Hokum Coco]

Feather plucking can be caused by disease or allergy. It can be a reaction to toxins or the result of a skin infection. Parasites, as well as dietary deficiencies, contribute to feather plucking. Some feather plucking is a behavioral response alone, with no medical cause (in other words boredom). Because feather plucking has such a range of causes, finding the cause takes some investigation on your part.
Good luck!
Sorry I could not be of some help.

Oh! Once I read you post a second time; That may just be a broody patch plucking to incubate eggs.

Perfectly normal.